In order to conduct rail operations safely and securely, operators need reliable train connectivity. With the advent of Intelligent Transport Systems, there are increased demands from this connectivity. This paper introduces the capabilities of 3GPP standard radio technology to meet the railway operator’s connectivity needs using a unified radio infrastructure. 3GPP is the 3rd Generation Partnership Project and provides the standards known to the public as 3G or 4G mobile telecommunications provided by the cellular phone operators. Recent developments in 3GPP standards make the technology suitable for use in both urban and mainline rail environments based on a private 4G LTE network owned and operated by the railroad agency. Since the 3GPP standard equipment ecosystem is shared by mobile operators, public safety agencies, utilities, and airports, the equipment cost is reduced compared to proprietary wireless techniques due to economies of scale. Using a dedicated radio network, all rail applications requiring wireless connectivity can traverse over a single radio infrastructure.
These rail applications include: CCTV real time passenger surveillance, mission critical push-to-talk voice, train control signalling (CBTC, ETCS or PTC), train telemetry, including real-time condition-based monitoring and passenger information systems. Using Quality of Service prioritization and pre-emption inherent to the LTE radio system, the mission critical railway applications always receive priority over non-mission critical functions. The FCC has recently announced the availability of the 3.5 GHz band to the public based on spectrum sharing. Spectrum sharing could be an acceptable option for railway application, provided it was given priority for mission critical functions. Current advances in LTE radio, notably Massive MIMO (multiple input, multiple output) antenna arrays, can provide coverage in 3.5 GHz band to a distance of over 1400 yards — which is less than the typical distance between stations. this transit agency dedicated network. Alternately sharing spectrum with Firstnet 700 MHz band should be explored.
